I tested the new Oura Ring 4 – here’s why it’s the best smart ring

The Apple Watch helped create the booming smartwatch market a decade ago, but the next big thing in wearables has been a slow burn. The tech industry thinks the hit it has been looking for is smart rings, small jewellery-like rings with sensors to track similar health metrics to smartwatches.

The attraction to smart rings over their watch counterparts is they are smaller, subtler and have longer battery life. With no screen to drain power or ping constantly distracting you from real life, tech heavyweight Samsung recently stepped into the breach with its first Galaxy Ring.

But the market leader in smart rings is ŌURA, a Finnish company that has been selling various versions of its Oura Ring since 2015. The third-generation ring catapulted the company into mainstream appeal thanks to famous wearers such as Prince Harry and Jennifer Aniston. A once-small firm shaping the industry in this way reminds me of Pebble, the monochrome E Ink smartwatch company that pre-dated the Apple Watch.

Earlier in 2024 I reviewed the Oura Ring 3 and enjoyed the design and health insights, but found the device too chunky to forget I was wearing it. That coupled with the high cost and mandatory monthly subscription left me feeling it wasn’t for everyone.

Now the Oura Ring 4 is here, and it is promising a slimmer fit along with improved sensors and a new algorithm called Smart Sensing that ŌURA claims can process more accurate health data. I’ve been wearing the new ring for two weeks and I already prefer it over the previous model.

The question to ask yourself is do you actually need one?

The Oura Ring 4 is a fully round ring designed to be worn on the index finger for the most accurate readings, though you can also wear it on your middle or third finger – not on your thumb or pinkie.

When you purchase the ring (from £349 with £5.99 monthly or £69.99 annual subscription), ŌURA will send you a sizing kit with plastic mock-up rings in sizes 4-15. This is essential, as you can’ return or exchange the ring once you’ve picked a size, so the kit lets you wear a few sizes for a day or so to work out which is most comfortable.

I opted for a size 11 in silver for my left index finger. This shiny model scratches easily, which I quite like as it will likely age in appearance like regular rings. If you want to avoid this look, there are matt finish options.

Thanks to unobtrusive sensors on the inside that sit next to your skin, the Oura Ring 4 can record your ongoing heart rate, blood oxygen levels, temperature and respiratory rate, collating all the data into charts and numbers within the companion smartphone app.

Some of these measurements include readiness, sleep and activity, all of which are scored out of 100. The ring can also help you track your menstrual cycle. The app presents a simple and effective way for you to see at a glance if the ring thinks your body is ready to exercise, if you slept well, and if you hit your set activity goal yet that day. You can also view metrics on stress.

After all this, it’s worth noting that ŌURA says: “Oura Ring is not a medical device and is not intended to diagnose, treat, cure, monitor, or prevent medical conditions/illnesses.”

One of the best things about the Oura Ring is you can wear it day and night for about a week. Unlike a smartwatch, which needs to be removed to charge almost daily and may be too bulky to comfortably sleep in, the ring can quietly be worn and rack up days of data without intrusion. The app will ping you when the ring needs a charge, which you do by placing it on the charging puck and juice up via USB-C. It only takes about an hour.

I’ve found the insights useful. The Oura app has significantly improved in 2024 and can surface more interesting, and seemingly accurate, data than before. Wear this device for a month and you’ll have detailed overviews of your sleep patterns and quality, stress levels, heart rate and general activity. The app is now much better at telling you useful things about this data, such as why you could be stressed, even suggesting you listen to five minute coaching sessions thanks to a partnership with popular mental health app Headspace.

Because of things like this I can now better appreciate the value of the subscription plan that you need to pay for – it’s impossible to use the Oura Ring without it. The Samsung Galaxy Ring doesn’t have a subscription and costs £399, but that product feels more like a companion to a Galaxy phone and Galaxy Watch.

It’s not much use on its own compared to the Oura Ring, which costs between £349 and £399 depending on the design you choose. The £5.99 per month is basically because Oura needs to make money. But this is a device you can wear on its own and still see big benefits, even if it’s just pointing out you shouldn’t drink alcohol after 9pm (correctly so).

Often technology is most successful when it’s at its simplest and appeals to our sense of identity. That’s why the Oura Ring 4 is a great product. It’s a simple ring with no screen, no vibrations, no notifications and week-long battery life. Put it on and get on with it. Feel better about your healthy choices. Be like Prince Harry. Good vibes.

The ring has its downsides. I found it clunking against my phone in my hand and I have to take it off to do the washing up. It’s the same price as most decent smartwatches but does less, and the subscription is understandable but yet another cost to add to my monthly bills. But most of all, do I really need one? I usually know that I’ve had a bad night’s sleep and I’ve been lazy this week. Do I really need an expensive gadget to tell me the same things?

Ask yourself these same questions before investing in the Oura Ring 4, but if you think it’s something you’ll find useful, then you probably will love it.